The operation of our multiuser facility for amino acid analysis in the second year of the award will follow the general format adopted thus far. Therefore, we expect to continue to receive protein and peptide samples from an increasing number of investigators at the University of Chicago and from other institutions in the surrounding area. We will continue to provide the technical expertise for acid hydrolysis of these samples under a variety of conditions that permit quantitation of each amino acid, including cysteine (cystine) and tryptophan. Samples will be analyzed on the Durrum D-502 analyzer funded by this award, or on an older D-500 instrument that we have used for the past 5 years. Results will be transmitted to each user of the facility in such a way that quantitation is provided for each amino acid in nanomoles or in moles per cent. If our experience in recent months is any indication of things to come, we should be involved with an ever-increasing demand on our analytical facility.